Biology

Prof. Gaiti Hasan
National Centre for Biological Sciences, Bangalore

Abstract:

Inositol-1,4,5 trisphosphate (IP₃) is a key cellular signaling molecule that functions downstream of specific G-protein coupled receptors and links GPCR activation to changes in intracellular Ca²⁺.  The primary cellular target of IP₃ is the endoplasmic reticulum localized ligand-gated calcium channel, the IP₃ receptor (IP₃R).  We also study the consequences of store-operated calcium entry (SOCE), which is stimulated upon IP₃-mediated Ca²⁺ release from the ER-store. My group’s interest is to understand the developmental and physiological consequences of IP₃ signaling and SOCE in neurons in the context of the whole organism. This requires that we perturb IP₃R function and SOCE specifically in neurons and not in other cell types. The ubiquitous expression of the IP₃R as well as STIM and Orai in multiple cell types in all multicellular organisms is a challenge for achieving this aim. Traditionally, cellular functions of ubiquitous proteins have been addressed using pharmacological methods on cells in culture. However, this approach does not allow an understanding of the physiological and/or developmental function of the targeted protein in the context of the whole organism. Sophisticated genetic tools, either available or developed by us in the fruit fly Drosophila melanogaster, have helped in understanding the consequences of cell and tissue specific abrogation of IP₃R function as well as SOCE. I will discuss our recent findings in this area.